Abstract: The invention relates to a process for the continuous production of a chemically uniform copolymer comprising 15 to 50% by weight of acrylonitrile and from 85 to 50% by weight of vinyl chloride and, optionally, up to 4% by weight of at least one other copolymerized ethylenically unsaturated comonomer containing acid groups by emulsion polymerization, wherein the copolymerization reaction is carried out with a monomer ratio of acrylonitrile to vinyl chloride of from 0.02 to 0.5, in the presence of a redox catalyst and in an acidic medium.

Abstract: In a photopolymerizable composition comprising(a) at least one ethylenically unsaturated photopolymerizable monomer.(b) at least one photoinitiator selected from organic mono- and/or di-carbonyl compounds and(c) a photoactivator, the improvement which comprises employing as said photoactivator at least one alkylaminoarylsulphonyl compound of the formula ##STR1## in which R.sub.1 and R.sub.2 each independently is a hydrogen atom or an alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl group which has 1 to 11 carbon atoms and is optionally substituted by at least one hydroxyl, amino, epoxy, urethane, urea, ether of ether group, or R.sub.1 and R.sub.2 together form a 3- to 6-membered ring, which optionally contains nitrogen, oxygen or sulphur as a hetero-atom,R.sub.3 independently of R.sub.1, has any of the meanings given for R.sub.1 or is a group of the formula ##STR2## R.sub.4 and R.sub.

Abstract: This invention relates to a process for the graft polymerization of (A) from 95 to 40 parts, by weight, of at least one ethylenically unsaturated monomer in the presence of (B) from 5 to 60 parts, by weight, of a partially or completely cross-linked rubber, in which the one or more than one monomer (A) and rubber (B) in the form of a latex or of a dispersion in an organic solvent are polymerized in an aliphatic hydrocarbon as reaction medium at from 30.degree. to 100.degree. C., using a radical forming initiator, and the graft polymerization product obtained as a sedimenting suspension of particles having an average diameter of from 5 to 1,000 .mu.m is isolated.

Abstract: A homopolymer or copolymer which contains, as a monomer unit, at least one styrene of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 independently of one another denote hydrogen, fluorine or partly or completely fluorinated alkyl or alkoxy andR.sup.4 and R.sup.5 independently of one another represent hydrogen or fluoride, the total number of fluorine atoms in the radicals R.sup.1 to R.sup.5 being at least 3 and the total number of carbon atoms in the radicals R.sup.1 to R.sup.3 being at most 8. The homo- or copolymers can be prepared by vinyl polymerization. They are useful as lenses or other components in an optical system where they have a refractive index n.sub.D of 1.42 to 1.55 with an Abbe number v.sub.D of 30 to 50.

Abstract: Modified olefine polymers of 20 to 98 parts by weight of an olefine homopolymer or copolymer and 0.5 to 80 parts by weight of a polymer containing aliphatic polyester blocks, which polymers are chemically linked through 0.5 to 40 parts by weight of a polymer of a monomer containing olefinic double bonds, a method for their manufacture, and their employment as moulding compositions.

Abstract: Polymer beads having an average bead diameter of from 5 to 500 .mu., consisting of an inorganic fine-particled filler and polymerized (meth)acrylic acid esters, and a process for their production, wherein a mixture of monomer and, optionally, polymer which is soluble in the monomer, which has a viscosity of from 0.1 to 10 Pa.s, measured at the dispersion temperature, and filler is suspended in an aqueous medium in the presence of dispersants and is polymerized.

Abstract: Acrylonitrile polymers and copolymers with good affinity for basic dyes without sulfonic acid groups containing comonomers are obtained by polymerizing at a temperature of from 0.degree. to 60.degree. C. in an aliphatic hydrocarbon having a boiling point of from -10.degree. to 80.degree. C. or in a mixture of aliphatic hydrocarbons having boiling points in the range from -10.degree. to 80.degree. C. using an initiator system comprising from 0.1 to 8.0 mole percent of sulfur dioxide, from 0.1 to 2.0 mole percent of a hydroperoxide which is soluble in the reaction medium and from 0.01 to 1.0 mole percent of an acid which is soluble in the reaction system in that polymerization is carried out continuously and in that an average residence time of from 10 minutes to 2 hours is maintained.

Abstract: The invention includes dental materials based on organic plastics in paste form, comprising at least one phase consisting essentially of finely divided, crosslinked plastics which contain copolymerized ester(s) of methacrylic acid to the extent of at least 50% by weight, and the second phase consisting essentially of ester(s) of methacrylic acid to the extent of at least 50% by weight. The materials can be used for making prostheses, crowns, bridges, artificial teeth, dental fillings, etc.

Abstract: A process for the polymerization of methyl methacrylate or mixtures thereof with up to 25%, by weight, based on total monomer, of vinyl monomers copolymerizable therewith, wherein polymerization is carried out in the presence of from 0.01 to 10%, by weight, based on total monomer, of one or more enol ethers derived from aliphatic or cycloaliphatic aldehydes or ketones.

Abstract: The invention relates to a process for the production of a chemically uniform acrylonitrile vinyl chloride copolymer in an aqueous emulsion in the presence of a redox catalyst and with a fluctuating concentration of at least one iron salt in the reaction medium wherein the polymerization reaction is carried out at a pH value of from 2 to 6 in the presence of a mixture of an iron salt and a complex former, the complex former having certain apparent stability constants of the iron-II-complex and of the iron-III-complex.

Abstract: The invention relates to a homopolymer or copolymer of acrylonitrile which comprises from 0 to 30% by weight, incorporated by polymerization, of comonomer units which are free from ionic groups, said polymers having a K-value of from 50 to 100, a dye absorption capacity for cationic dyes of at least 0.5% by weight, a conductivity, measured in dimethylformamide solution, of at least 10.mu. Siemens, and from 0.2 to 1.5% by weight of sulphur fixed to said polymer as well as to a process for the production thereof.

Abstract: A dental material is provided based on organic plastics in paste form, which consists essentially of (a) a polymerizable binder, (b) a crosslinked bead polymer and (c) a fine-particled inorganic filler.

Abstract: The invention provides dental materials which are opaque to X-rays and are based on organic plastics in paste form, which comprises (a) a polymerizable binder, (b) a crosslinked bead polymer and (c) an X-ray contrast medium. The materials can also contain as an additional component (d) a fine-particled inorganic filler which is not opaque to X-rays. The materials are useful, inter alia, for filing dental cavities.

Abstract: The invention relates to bead polymers, useful in the provision of dental articles and made by bead polymerizing a diamine-lengthened polyurethane and a methacrylate. Also included in the invention are the dental articles made using said bead polymers.

Abstract: The present invention relates to a process for the preparation of bis-carbonic acid aryl esters of polyester-diols, lengthened via --OCOO-- groups, characterized in that polyester-diols with molecular weights Mn (number-average) of over 250, preferably over 600, are heated with carbonic acid bis-aryl esters at temperatures between about 100.degree. C. and 200.degree. C., preferably between about 110.degree. C. and 180.degree. C., in vacuo below about 35 mm Hg, preferably between about 25 and 1 mm Hg, in the presence of catalysts, less than one mol of carbonic acid bis-aryl ester being employed per OH group of the polyester-diol and the hydroxyaryl compounds formed being distilled off.

Abstract: Bead polymers having a mean bead diameter of from 10 to 200.mu. of one or more polymerized viscous methacrylates and/or dimethacrylates having a viscosity of from 0.5 to 500 Pa.s and, optionally, up to 20% by weight of one or more other vinyl monomers.

Abstract: A thermoplastic molding composition contains a mixture of 10 to 95% by weight of a vinyl chloride polymer and 90 to 5% by weight of an adipate/carbonate mixed ester which is the transesterification reaction product of an adipate-diol polyester having terminal hydroxyls and a bifunctional carbonic acid aryl ester. The composition has a favorable combination of physical properties which include good cold fracture behavior coupled with easy processability and good ageing characteristics.

Abstract: This disclosure is concerned with a single step process for the production of diphenol terminated polycarbonates by the transesterification of diphenols, bis-aryl carbonates and polymeric diols with aliphatically bound terminal hydroxyl groups. These diols are selected from polyesters, polyethers, polythioethers and polyacetals. The transesterification is carried out at elevated temperatures under vacuum optionally in the presence of a catalyst with the ratios of the reactants being such as to avoid the retention of any terminal aliphatic hydroxyl groups or aryl carbonate groups.

Abstract: The invention relates to a process for the production of polyacrylonitrile or acrylonitrile copolymers, the polymerization being carried out at a temperature of from -40.degree. to +60.degree. C. optionally under pressure in an aliphatic chlorofluorine or fluorine substituted hydrocarbon containing up to 8 carbon atoms and having a boiling point of from -60.degree. to +50.degree. C. or in mixtures thereof having boiling ranges of from -60.degree. to +50.degree. C. and using a starter system comprising a hydroperoxide sulphur dioxide and an acid. The system may also contain aliphatic hydrocarbons in such quantities that a non-inflammable mixture is formed.

Abstract: A two-phase bead polymer having an average bead diameter of 10 to 120.mu., and comprising (A) 88 to 99.5% by weight of a polymer of polymerized units of at least one methacrylic acid ester containing from 1 to 10 carbon atoms in the aliphatic, saturated alcohol component, the methacrylic ester polymer, optionally, containing up to 30% by weight of copolymerized units of at least one monomer selected from acrylic acid esters containing from 1 to 10 carbon atoms in the aliphatic saturated alcohol component, hydroxyalkyl esters of methacrylic acid containing from 2 to 4 carbon atoms in the alkyl group, styrene, vinyl acetate, (meth)acrylamide, (meth)acrylic acid and/or itaconic acid, and (B) 0.5 to 12% by weight of a polyurethane.